Locking mechanism for two telescoping poles of a power tool

ABSTRACT

A power tool is provided with a telescopic pole including a first pole configured to telescopingly move in an out of a second pole. A locking mechanism is provided including a first section configured to connect to the second pole and a second section configured to connect to the first pole. The first section includes a sheath mountable on and surrounding at least part of the second pole, a resilient tab connected to the sheath, and a catch formed on the tab. The catch is configured to locate within the recess of the second pole when the sheath is mounted on the second pole.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority, under 35 U.S.C. § 119, to GB PatentApplication No. 2001235.7, filed Jan. 29, 2020.

FIELD

The present invention relates to a locking mechanism for a telescopicpole of a power tool, such as, a pole sander.

BACKGROUND

Pole sanders typically comprise a telescopic pole with a sanding headpivotally mounted on one end. The sanding head comprises a hood whichsurrounds a platen which is mounted on an output spindle which projectsfrom the hood. Sandpaper can be attached to the platen for sanding awork surface. Alternatively, a polishing pad can be attached to polish awork surface. The output spindle and hence the platen, is rotated by anelectric motor. The electric motor can be mounted on the sanding head.Alternatively, the motor can be mounted on the end of the telescopicpole remote from the sanding head. A vacuum cleaner can be attached tothe sanding head, typically via a pipe which extends through thetelescopic pole, to remove dust generated by the sanding action of therotating platen from under the hood.

Examples of pole sanders are disclosed in EP0727281, EP2033738,DE102014103019, WO2014/086873, EP3083139 and DE102014112355.

FIG. 28 discloses a prior art design of locking mechanism 200 for atelescopic pole of a pole sander. The telescopic pole comprises a firstpole which slides in and out of a second pole to enable the length ofthe pole sander to be adjusted, the first pole locating inside of thesecond pole when the telescopic pole is adjusted to its shortest length.

The locking mechanism comprises a sleeve 600 which has a first section602 and a second section 604. The first section 602 is used to attachthe locking mechanism 200 onto the second pole of the pole sander. Thesecond section 604 forms a clamp which can be releasably tightenedaround the first pole in order to releasably axially lock the first poleto the second pole.

The first section 602 comprises a resiliently deformable first C shapedsleeve 606 with two parallel flaps 612 extending from the edges of thefirst C shaped sleeve 606. A gap (indicated by Arrow 608) is formedbetween the two flaps 612. When no external forces are applied to thefirst C shaped sleeve 606, the first C shaped sleeve 606 is held in apre-set shape with a pre-set cross-sectional area with the width of thegap 608 between the flaps 612 being held at a pre-set distance by theresilient nature of the first C shaped sleeve 606. The first C shapedsleeve 606 can be deformed using a bolt 610 which passes through theflaps 612 in such a manner that the width of the gap 608 can bedecreased from the pre-set width, reducing the size of the pre-setcross-sectional area of the first C shaped sleeve. When no force isapplied by the bolt 610, the first C shaped sleeve 606 reverts to thepre-set shape with the width of the gap 608 reverting to the pre-setdistance.

Formed through each flap 612 is a hole (not shown). The diameter of thehole is slightly larger than that of the shaft (not shown) of the bolt610 but less than the head 614 of the bolt 610. The shaft of the bolt610 is inserted through one hole in one flap 612 and through the otherhole in the second flap 612. A nut (not shown) is then threaded onto thefree end of the shaft of the bolt 610. As the nut is screwed onto theshaft of the bolt 610, the two flaps 612, which are sandwiched betweenthe head of the bolt 610 and the nut, move towards each other as the nutis screwed onto the shaft reducing the width of the gap 608.

Formed in each side of the first C shaped sleeve is an elongate slot 616which extend from the edges of the first C shaped sleeve 606 up thesides of first C shaped sleeve 606 to a second hole 618. The elongateslots 616 and second holes 618 are capable of engaging ridges and/orpegs (not shown) on the second pole of the pole sander.

The locking mechanism 200 is attached to the second pole of the polesander as follows. The first pole is separated from the second pole. Thenut is unscrewed from the bolt 610 (whilst the shaft of the bolt 610remains in the two holes of the faps 612) to allow the first C shapedsleeve 606 of the first section 602 to revert to its pre-set shape withthe width of the gap 608 between the flaps 612 reverting to the pre-setdistance. The first C shaped sleeve 606 of the first section 602 is thenslid onto the end of the second pole, with the elongate slots 616 andsecond holes 618 aligning with ridges and pegs formed on the outersurface of the second pole. The nut is then screwed onto the shaft ofthe bolt 610, the two flaps 612 which are sandwiched between the head614 of the bolt 610 and the nut, being moved towards each other,reducing the width of the gap 608 and the size of the cross-sectionalarea of the second C shaped sleeve. This results in the elongate slots616 and second holes 618 engaging with and holding onto the ridges andpegs formed on the outer surface of the second pole in addition to thefirst C shaped sleeve engaging with and holding the outer surface of theend of the second pole as the cross-sectional area is reduced. The nutis tightened until the first C shaped sleeve 606 is firmly secured tothe second pole. The first pole is then inserted through the secondsection 604 of the locking mechanism 200 and into the second pole. Theclamp of the second section 604 is then used to lock onto the first poleto secure the first pole within the second pole.

The second section 604 is described with reference to FIGS. 28 and 29 .The second section 604 comprises a resiliently deformable second Cshaped sleeve 630 with two parallel flaps 632 extending from the edgesof the second C shaped sleeve 630. A gap (indicated by Arrow 634) isformed between the two flaps 632. When no external forces are applied tothe second C shaped sleeve 630, the second C shaped sleeve 630 is heldin a pre-set shape with a pre-set cross-sectional area with the width ofthe gap 634 between the flaps 632 being held at a pre-set distance bythe resilient nature of the second C shaped sleeve 630. The second Cshaped sleeve 630 can be deformed using a bolt 636, which passes throughthe flaps 632, and a cam 638 attached to the bolt 636 in such a mannerthat the width of the gap 634 can be decreased from the pre-set width.When no force is applied by the bolt 636 and cam 638, the second Cshaped sleeve 630 reverts to the pre-set shape with the width of the gap634 reverting to the pre-set distance.

Formed through each flap 632 is a hole (not shown). The diameter of thehole is slightly larger than that of the shaft 640 of the bolt 636 butless than the head 642 of the bolt 636. The shaft 640 of the bolt 636 isinserted through one hole in one flap 632 and through the other hole ofthe second flap 632. A nut 644 is then threaded onto the free end of theshaft 640 of the bolt 636. The nut 644 is screwed onto the shaft 640 ofthe bolt 636 until the two flaps 632 are sandwiched between the head 642of the bolt 636 and the nut 644 and the flaps 632 have been moved to asecond pre-set distance from each other, the two flaps 632 being heldagainst the head of the bolt 636 and the nut 644 by the resilient natureof the second C shaped sleeve 630 urging the flaps 632 apart.

The cam 638 is pivotally mounted on a rod 646 which passes though thehead 642 of the bolt 636. The cam 638 can pivot about an axis, whichextends longitudinally along the length of the rod 646, perpendicularlyto the longitudinal axis of the shaft 640 of the bolt 636. An edge 648of the cam 638 abuts against the side of one of the flaps 632. The cam638 is circular in shape with the rod 646 locating eccentricallyrelative to the centre of the circular cam 638. As such, as the cam 638is rotated, the distance of the edge 648 of the cam 638, which abutsagainst the side wall of the flap 632, from the rod 646 changesdependent on the angular position of the cam 638 relative to the flap632. The side wall of the flap 632 remains in contact with the edge 648of the cam 638 due to the resilient nature of the second C shape sleeve630 which biases the two flaps 632 away from each other with one of theflaps 632 being biased into engagement with the edge 648 of the cam 638.Attached to one side of the cam 638 is an arm 658 which is curved alongits length. The arm 658 is used by an operator to rotate the cam 638 inorder to move the flap 632 abutting against the edge 648 of the cam 638,altering the size of the gap between the two flaps 632 between a largegap and a small gap, the flaps 632 being moved due to the resilientnature of the second C shaped sleeve 630. A groove 650 is formed aroundthe second section 604. The curve of the arm 658 is the same as thecurve of the base of the groove 650. When the arm 658 is pivoted so thatit is perpendicular to the base of the groove 650, the size of the gapbetween the flaps 632 is the greatest (when the position of the nut 644on the shaft 640 of the bolt 636 remains fixed). When the arm 658 ispivoted so that it is locates within the groove 650 so that the arm 658is flush with the base of the groove 650 (whilst the position of the nut644 on the shaft 640 of the bolt 636 remains fixed), the size of the gapbetween the flaps 632 is the smallest.

The operation of the clamping mechanism of the second section 604 willnow be described. The locking mechanism is attached to the end of thesecond pole as described above. The arm 658 of the second section 604 isthen pivoted so that it is perpendicular to the base of the groove 650so that the size of the gap between the flaps 632 is the greatest. Thisresults in the largest cross-sectional area of the second C shapedsleeve 630 which is greater than the cross-section area of the firstpole. The first pole is then inserted through second C shaped sleeve 630of the second section 604 of the locking mechanism 200 and into thesecond pole. The arm 658 is then pivoted so that it is located in thegroove 650 flush with the base of the groove 650 so that the size of thegap between the flaps 632 is the smallest. This results in the smallestcross-sectional area of the second C shaped sleeve 630 which is slightlysmaller than the cross-section area of the first pole. As such, thesecond C shaped sleeve 630 engages with and holds the outer surface ofthe first pole as the cross-sectional area is reduced. This locks thefirst pole to the locking mechanism which in turn is attached to thesecond pole.

The problem with the design of the first section 602, which is used toattach the locking mechanism 200 to the second pole, is that the nut andbolt can be over tightened resulting in excess compressional force beingapplied to the first C shaped sleeve 606, resulting in the end of thesecond pole becoming deformed. If the first pole is located inside ofthe end of the second pole, the excessive compressive force can resultin the second pole engaging with the first pole if it becomes deformed,preventing movement of the first pole within the second pole. As such,the position of the first pole becomes permanently fixed to the secondpole and therefore cannot be telescoped in or out of the second pole,regardless of whether the clamping mechanism of the second section 604is released or clamped.

SUMMARY

The present invention provides an alternative way of attaching thelocking mechanism to the second pole which avoids the problemsassociated with the prior art design described with reference to FIGS.28 and 29 .

According to a first aspect of the present invention, there is provideda locking mechanism capable of locking the position of a first polerelative to a second pole of a power tool comprising a telescopic polecomprising at least two poles, the first pole capable of telescoping inand out of the second pole, the second pole comprises at least onerecess. In an embodiment, the locking mechanism includes a first sectioncapable of connecting to the second pole of a power tool and a secondsection capable of connecting to the first pole of a power tool. In anembodiment, the first section comprises: a sheath which is capable ofmounting on and surrounding at least part of the second pole; aresilient tab connected to the sheath; and a catch formed on the tab,wherein the catch is capable of locating within the recess of a secondpole when the sheath is mounted on the second pole.

According to a second aspect of the present invention, there is provideda power tool comprising a telescopic pole comprising at least two poles,a first pole capable of telescoping in and out of a second pole whereinthe second pole comprises at least one recess; and a locking mechanismcapable of locking the position of the first pole relative to the secondpole, the locking mechanism comprising a first section capable ofconnecting to the second pole and a second section capable of connectingto the first pole. In an embodiment, the first section comprises: asheath which is capable of mounting on and surrounding at least part ofthe second pole; a resilient tab connected to the sheath; and a catchformed on the tab, wherein the catch locates within the recess when thesheath is mounted on the second pole.

In either aspect of the invention, the recess can be a window whichextends through the wall of the second pole. The catch can extendthrough the window.

In either aspect of the invention, the catch may comprise a taper.Furthermore, the sheath may mount on and surround the end of the secondpole. The resilient tab may be connected at one of its ends to thesheath.

In either aspect of the invention, there may be provided a cut out inthe wall of the sheath, the tab being connected at one of its ends to anedge of the cut out, the tab extending, at least in part, across atleast part of the cut out. The at least part of the tab may extendwithin the plane of the cut out.

In either aspect of the invention, the tab may extend in a directionparallel to the longitudinal axis of the sheath.

In either aspect of the invention, the tab may be planar.

In either aspect of the invention, the cut out may rectangular in shape.

In either aspect of the invention, the longer edges of the rectangularcut out may extend in a direction parallel to the longitudinal axis ofthe sheath.

In either aspect of the invention, the tab may connect to one of theshorter edges of the cut out.

In either aspect of the invention, the catch may be formed on the tabadjacent the end of the tab.

In either aspect of the invention, the catch may extend in a directionperpendicular to that of the plane of the tab.

In either aspect of the invention, the tab may flex to allow the catchto move in a direction perpendicular to that the longitudinal axis ofthe sheath.

In either aspect of the invention, the tab may locate inside of thesecond pole. The catch may project from inside of the second pole intothe recess.

In either aspect of the invention, when the first pole is located insideof the second pole, the first pole locates behind the tab to preventmovement of the tab, locking the catch within the recess.

According to a third aspect of the present invention there is providedmethod of attaching a locking mechanism in accordance with either thetwo previous inventions comprising the step of:

1) sliding the sheath of the locking mechanism onto the end of thesecond pole until the catch engages with the recess, where the catchcomprises a taper;

2) sliding the sheath onto the end of the pole until a front edge (673)engages with the taper of the catch;

3) continuing to slide the sheath onto the pole to cause the catch tomove out of the way by bending the resilient tab with the front edgingslidingly engages the taper;

4) continuing to slide the sheath onto the pole until the catch alignswith the recess;

5) allowing the catch to enter the recess under the biasing force of theresilient tab.

The method may further comprise the step sliding the catch along insidewall of the second pole after it has been moved out of the way prior toaligning with the recess.

The tab may locate inside of the second pole when the catch has beenmoved out of the way and/or when the catch is aligned with the recessand/or when the catch has entered the recess.

The method may further comprise the step of sliding the first pole intothe second pole to abut against the tab to lock the catch in the recess.

In any of the three aspects of the invention, the first pole may acomprise a single aluminium tube with an internal wall to form twopassageways; wherein the second pole may comprise a first tube and asecond tube mounted in parallel to the first tube, inside of the firsttube, wherein an end of the second tube of the second pole locatesinside one of the passageways of the tube of the first pole; and whereinthe tube and internal wall of the first pole locate inside of the firsttube of the second pole.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings described herein are for illustrative purposes only ofselected embodiments and not all possible implementations and are notintended to limit the scope of the present disclosure.

FIG. 1 shows a top view of the pole sander;

FIG. 2 shows a side view of the pole sander;

FIG. 3 shows a vertical cross-sectional view of the pole sander;

FIG. 4 shows a perspective view of the sanding head;

FIG. 5 shows an underside view of the sanding head with the platenremoved;

FIG. 6A shows a vertical cross-sectional view of the edge of the sandinghead;

FIG. 6B is the same as FIG. 6A with the addition of hatching to showcross sectional area of gap between edge of the platen and the innerwall;

FIG. 7 shows a perspective view of the brush ring;

FIG. 8 shows a view of part of the top side of the plate with the leafspring of the brush ring 132 passing through an aperture from below theplate to attach to the top side of the plate;

FIG. 9 shows a schematic diagram showing how the two poles of theelongate body are telescopically connected to each other;

FIG. 10 shows the seals which connect between the two poles of theelongate body;

FIG. 11A shows the seal for the first pole 196 being attached to thefirst pole 196;

FIG. 11B shows a vertical cross section of the seal for the first pole196 being attached to the first pole 196;

FIG. 11C shows the seal for the first pole 196 mounted on the first pole196;

FIG. 12 shows the seals adjacent the ends of the aluminium tubes of thepoles;

FIG. 13 shows a perspective cross section showing how the aluminiumtubes and seals of the two poles of the elongate body are telescopicallyconnected to each other;

FIG. 14 shows a perspective cross section showing how the aluminiumtubes and seals of the two poles of the elongate body are telescopicallyconnected to each other;

FIG. 15 shows a top view of the sanding head;

FIG. 16 shows a vertical cross section of the sanding head and lower endof the first pole 196;

FIG. 17 shows the underside view of the sanding head including theplaten;

FIG. 18 shows the platen;

FIG. 19 shows the rear housing with one of the clam shells removed;

FIG. 20 shows a vertical cross section of the rear housing;

FIG. 21 shows a top perspective view of the sanding head;

FIG. 22 shows the extension tube inside the handle section of the rearhousing with the vacuum nozzle detached;

FIG. 23 shows the extension tube inside of the handle section of therear housing with the vacuum nozzle attached;

FIG. 24 shows the rear end of the extension tube with the vacuum nozzledetached;

FIG. 25 shows the rear end of the extension tube with the vacuum nozzleattached;

FIG. 26A and FIG. 26B show a first angle of the tubular passageway ofthe hood;

FIG. 27A and FIG. 27B shows a second angle of the tubular passageway;

FIG. 28 shows a prior art of locking mechanism for a telescopic pole ofa pole sander;

FIG. 29 shows a sketch of a cross section of the prior art lockingmechanism in the direction of Arrows M shown in FIG. 28 ;

FIG. 30 shows a locking mechanism according to the present inventionmounted on the elongate body of a pole sander;

FIG. 31 shows an exploded view of the first and second poles of theelongate body together with the locking mechanism as shown in FIG. 30 ;and

FIG. 32 shows a cross sectional view of the locking mechanism mounted onthe elongate body of a pole sander shown in FIG. 30 .

Corresponding reference numerals indicate corresponding parts throughoutthe several views of the drawings.

DETAILED DESCRIPTION

FIG. 1 shows a top view of the pole sander. FIG. 2 shows a side view ofthe pole sander. FIG. 3 shows a vertical cross-sectional view of thepole sander along a plane 3 of FIG. 1 . Referring to FIGS. 1 to 3 , thepole sander comprises a sanding head 100 pivotally attached to one endof an elongate body 102 and a rear housing 104 attached to the otherend.

The elongate body 102 is telescopic and is formed from two poles 196,198, one of which slides in an out of the other as described in moredetail below.

The sanding head 100 connects to the end of the elongate body 102 via apivot mechanism 110 which is described in more detail below. The sandinghead 100 comprises a hood 112 on top of which is mounted an electricmotor 114. The motor 114 is a DC brushless motor 114. The motor 114 isenclosed by a motor housing 120 which is cup shaped and surrounds thetop and sides of the motor 114. The motor housing 120 attaches to thetop of a gear housing 122 which encloses a planetary gear set 124. Thegear housing 122 mounts on top of the hood 112. The motor 114 isdrivingly connected via the planetary gear set 124 to an output spindle118 having a longitudinal axis 126 about which it rotates and which islocated below the hood 112. Attached to the end of output spindle 118 isa circular platen 116 which extends radially outwards from the outputspindle 118. When the motor 114 is activated, the motor 114 rotationallydrives the output spindle 118 and hence the platen 116 about a driveaxis 126.

A flexible dust extraction pipe 128 attaches to the top of the hood 112on one side of the motor 114. An aperture 130 is formed through the hood112. The end of the flexible pipe 128 surrounds the aperture 130. Assuch air can be drawn from beneath hood 112 through the aperture 130 andinto the flexible pipe 128. This enables dust and debris generatedduring the operation of the pole sander to be removed from under thehood 112 by applying a suction force to the flexible pipe 128. Theoperation of the dust extraction of the pole sander is described in moredetail below.

A brush ring 132 attaches to the edge of the hood 112. The brush ring132 is described in more detail below.

The rear housing 104 is formed two plastic clam shells which clamp tothe end of the elongate body 102. The rear housing 104 comprises aforward mount section 136 and rear handle section 138. A battery mount140 is formed on the lower surface of the mount section of the rearhousing 104. A battery pack 142 can be slid in a forward direction(Arrow M in FIG. 19 ) onto the battery mount 140 to attach it to therear housing 104 and in a rearward direction to detach it from thebattery mount 140. The design of the battery mount 140 and battery 142are known in art and therefore will not be described in any more detail.

Control electronics 144 for the motor 114 are mounted inside of forwardmount 136 section of the rear housing 104. The control electronics 144are connected to the motor 114 via an electric cable 146 which passesthrough a second passageway 148 of the elongate body 102 through thelength of the elongate body 102. The control electronics 144 control theoperation of the brushless motor 114.

A lock on/lock off switch 150 is mounted on the top of rear housing 104where the rear handle section 138 connects to the forward mount section136. An operator can use the lock on/lock off switch 150 to activate themotor 114.

An operator can support the pole sander by grasping the rear handlesection 138 of the rear housing 104 in one hand and the elongate body102 in the other. The operator can switch the pole sander on or offusing the thumb of the hand grasping the rear handle section 138.

A vacuum connection nozzle 152 is mounted on the rear of the rearhousing 104 which connects to a first passageway 154 which extendsthrough the length of the elongate body 102. The other end of the secondpassage 154 connects to the flexible pipe 128. A vacuum cleaner (notshown) can be connected to the nozzle 152 and draw air from under thehood 112, through the flexible pipe 128, through the first passage 154in the elongate body 102, through the nozzle 152 and into a vacuumcleaner.

The hood 112 will now be described with reference to FIGS. 4 to 6 .

The hood 112 comprises a circular plate 156 which extends radially froma central circular hole 158 through which the output spindle 118projects. Formed on the underside of the plate 156 around the edge is aperipheral wall 160 which projects perpendicularly to the plane of thecircular plate 156. An inner circular inner wall 162 is formed on theunderside of the plate 156 in close proximity to and concentrically withthe peripheral wall 160. The inner wall 162 has the same height as theperipheral wall 160 and extends in the same direction that is parallelto the peripheral wall 160. A circular trough 164 is formed between thetwo walls 160, 162. Six rectangular apertures 166 are formed through thebase of the trough 164. The apertures 166 are located equidistantlyaround the centre of the plate 156 in a symmetrical fashion. A chamberis formed between the inner wall 162 and the underside of the plate 156.

Formed through the plate 156 between the inner wall 162 and the centralhole is an arc shaped aperture 130 which allows air and debris to passthrough the plate 156. The aperture 130 has three edges, a firststraight edge 170 which extends tangentially to the longitudinal axis126 of the output spindle 118, a second edge 172 of equal length whichextends from the end of the first edge 170, perpendicularly to the firstedge 170, in a direction away from the longitudinal axis 126 of theoutput spindle 118, and a third curved edge 174 extending between theends of the first and second edges 170, 172. The circular plate 156 hasa radius R. The whole of the arc shaped aperture 130 is located at adistance of less than half of the radius from longitudinal axis 126 ofthe output spindle 118 or the centre of the plate 156 (<R/2).

Integrally formed on the top side of the plate 156 is a curved wall 178which forms a tubular passageway 176 from the arc shaped aperture 130 toan opening where the flexible pipe 128 is attached. Where the tubularpassageway 176 connects to the arc shaped aperture 130, it is shaped toengage with the arc shaped aperture 130 at certain angles to maximisethe air flow efficiency.

Referring to FIGS. 26A and 26B, the first angle of the exit of thetubular passageway 176 is located in a vertical plane 300 which passesthrough axis of rotation 126 of the output spindle 118 across the end ofthe tubular passage 176 adjacent the arc shaped aperture 130. The angle302 in this plane 300 between the axis of rotation 126 of the outputspindle 128 and the direction of the tubular passageway 176 is less than90 degrees (perpendicular) but greater than 0 degrees (parallel) and isideally between 20 degrees and 60 degrees.

Referring to FIGS. 27A and 27B, the second angle of the exit of thetubular passageway 176 is located in a vertical plane 304 which extendstangentially to the axis of rotation 126 of the output spindle 128, thepart of the plane 304 which passes through the exit of the tubularpassageway 176 being the closest part to the axis of rotation 126 of theoutput spindle 118. The angle 308 in this plane 304 between the plane ofthe circular plate 156 of the hood 112 and the direction of the tubularpassage 176 in the turning direction 306 of the platen 116 is less than90 degrees and is ideally between 20 degrees and 60 degrees.

The hood 112 is formed in a one-piece construction from plastic.

The brush ring 132 will now be described with reference to 6 to 8.

The brush ring 132 comprises a plastic circular ring 180 which is sizedso that it is capable of locating inside of the trough 164. Extendingperpendicularly from the bottom side of the ring 180 are a series ofbristles 182. Attached to the opposite top side of the brush ring 132are the ends 184 of six leaf springs 186. The leaf springs 186 areformed from sheet metal and are resiliently deformable in a directionperpendicular to the plane of the sheet. The leaf springs 186 comprisesa central section 188 located between two end sections 184, 190. The endsections 184, 190 extend in a direction parallel to the top surface ofthe ring 180. The central section 188 of the leaf springs 186 extendsupwardly at a slight angle to the plane of the circular ring 180. Eachcentral section 188 of each leaf spring 186 extends through therectangular aperture 166 in the trough 164 and attaches to the top side194 of the plate 156 as shown in FIG. 8 . The leaf springs 186 bias thering 180 to a position where it is located at a distance from the baseof the trough 164 as shown in FIG. 6 . In this position, the bristles182 project below the hood 112. When the sanding head 100 is placedagainst a work surface, the bristles 182 engage with the work surface.When the sanding head 100 is pushed against the work surface, the brushring 132 is pushed into the trough 164 against the biasing force of theleaf springs 186. The leaf springs 186 ensure that the bristles 182 arebiased into engagement with the work surface. When the sanding head 100is removed from the surface, the brush ring 132 returns to its originalposition due to the resilient nature of the leaf springs 186.

A plastic cover 195 is located over the topside of the hood 112enclosing the ends 190 of the leaf springs 186 attached to the top side194.

The telescopic elongate body 102 will now be described with reference toFIGS. 1 to 3 and 9 to 14 .

The pole sander has an elongate body 102 comprising a first pole 196which is capable of sliding in and out of a second pole 198 in atelescopic manner to enable the length of the pole sander to beadjusted. A locking mechanism 200 is used to lock the first pole 196 tothe second pole 198 when the two poles 196, 198 have been telescoped toa preferred length.

Inside both of the poles 196, 198 are two passageways 148, 154 which runthe length of the both poles 196, 198. The first larger passageway 154is used to transport air (due to suction) and entrained dust and debris,generated during the use of the pole sander, through the poles 196, 198from the working end to a vacuum nozzle 152 at the opposite end, thenozzle 152 being connected to a vacuum cleaner. The second smallerpassageway 148 is used as a conduit for electric cable 146 which providepower and control signals from a control electronics 144 for theelectric motor 114 mounted in the sanding head 100.

The first pole 196 comprises a single aluminium tube with an internalwall 202 located inside of the tube, which runs the length of the tubeto form the two passageways 148, 154 which run the length of the firstpole 196. The first larger passageway 154 forms part of the firstpassageway which is used to transport air. The second smaller passageway148 forms part of the passageway which is used as a conduit for theelectric cable 146. A first seal 204 attaches to the end of the firstpole 196 which is inserted into the second pole 198. The shape of thefirst seal 204 corresponds to that of the end of the aluminium tube andinternal wall 202. The first seal 204 provides a seal between the firstpole 196 and the second pole 198. It also acts as a slide bearing.

The second pole 198 comprises two aluminium tubes 206, 208. The secondaluminium tube 208 locates inside of the first aluminium tube 206 andruns the full length of the first tube 206, their longitudinal axesbeing parallel to each other. The second aluminium tube 208 forms partof the first passageway which is used to transport air and dust ordebris. The first aluminium tube 206 forms part of the passageway 154which is used as a conduit. A second seal 210 is attached to the end ofthe first aluminium tube 206 into which the first pole 196 is inserted.The shape of the second seal 210 corresponds to that of the end of thealuminium tube 206. A third seal 212 is attached to the end of thesecond aluminium tube 208 which is inserted into the second passage 148way of the first pole 196. The shape of the third seal 212 correspondsto that of the end of the second aluminium tube 208. The seals 210, 212provides a seal between the first pole 196 and the second pole 198. Theyalso act as slide bearings. The two tubes 206, 208 are connected to eachother at their ends remote from the seals 210, 212 so that relativemovement between the two tubes 206, 208 is prevented.

The poles 196, 198 are assembled as following. The end with the thirdseal 212 of the second aluminium tube 208 of the second pole 198 isinserted into the second passageway 148 of the first pole 196 throughthe third seal 212. The end of the first pole 196 with the first seal204, with the second aluminium tube 208 inside of it, is then insertedinto the end of the first aluminium tube 206 of the second pole 198 withthe second seal 210.

The poles 196, 198 can be telescopically locked using a lockingmechanism 200′ described below.

The larger passageway 154 in the first pole 196 connects directly to anend of the flexible tube via a collar. The larger passageway 154 in thesecond pole 198 connects to an end of the vacuum attachment nozzle 152via an extension tube 216.

As the poles 196, 198 are made from aluminium, they are conductive. Assuch the poles, 196, 198 are electrically grounded by being electricallyconnected to neutral in the electronic control electronics 144 in therear housing 104. In order to ensure that the whole of elongate body 102is grounded, ideally, the seals 204, 210, 212 are manufactured fromelectrically conductive material. This ensures a good electricalconnection between the two poles 196, 198.

In addition, or as an alternative, metal contacts 218 such as leafsprings, at least one electric cable and/or an electrical connector canbe connected between the telescopic poles 196, 198 to ensure electricalconductivity between the poles 196, 198. Ideally, they are locatedbetween the overlapping parts of the telescopic poles 196, 198.

Referring to FIGS. 30 to 32 , the locking mechanism 200′ for locking thefirst pole 196 to the second pole 198 according to the present inventionwill now described.

The locking mechanism comprises a sleeve 600′ which has a first section602′ and a second section 604′. The first section 602′ is used to attachthe locking mechanism 200′ onto the second pole of the pole sander. Thesecond section 604′ forms a clamp to releasably axially lock the firstpole to the second pole. The second section 604′ is the same as secondsection 604 of the prior art design described above with reference toFIGS. 28 and 29 in relation to the prior art design, and to the extentthat it includes the same feature, the same reference numerals are used.The first section 602′ is connected at a top half to the second section604′ by a bridge 660 but is separated at a bottom half by an elongategap 662.

The design of the first section 602′ is new and forms an embodiment ofthe invention as covered by the claims.

The cross-sectional shape of the aluminium tube the first pole 196 isoval. The cross-sectional shape of first aluminium tube 206 of thesecond pole 198 is also oval.

The first section 602′ comprises a tubular sheath 670 which has an ovalshape in cross-section and which is capable of sliding over the end ofthe first aluminium tube 206 of the second pole 198. A rectangular cutout 672 is formed through one side of the sheath 670 which forms anaperture through the side of the sheath 670. The cut out 672 isrectangular in shape, with the longer edges 674 of the rectangular cutout 672 extending in a direction parallel to a longitudinal axis 676 ofthe sheath 670. A resilient planar rectangular tab 678 is connected atone of its ends to a shorter edge 680 of the cut out 672, the tab 678extending across the cut out 672 in a direction parallel to the plane ofthe cut out 672 and, in its lengthwise direction, parallel to the longeredges 674 of the cut out 672. The resilient tab 678 is connected at oneend to the shorter edge 680 of the cut out 672 which is located closestto the section 604′. The free end of tab 678 can flex in a directionperpendicular to the plane of the cut out 672. The ratio of thedimensions of the shorter sides of the tab 678 to the longer sides ofthe tab 678 is the same as that of the ratio of the dimensions of theshorter edges 680 of the cut out 672 to the longer sides 674 of the cutout 672. The size of the sides of the tab 678 are slightly smaller thanthose of the cut out 672 leaving a gap between the longer sides of thetab 678 and the longer edges 676 of the cut out 672 and between the freeend of the tab 678 and the short edge 680 of the cut out 672 adjacentthe free end.

The thickness T1 of the tab 678, as best seen in FIG. 32 is less thanhalf of the thickness T2 of the sheath 670. The base 684 of the tab 678is co-planer (flush) with that of the inner wall 686 of the sheath 670.A catch 682 is formed on the tab 678 adjacent the free end of the tab678. The catch 682 extends in a direction perpendicular to the plane ofthe tab 678 away from the base 684 into the space formed within the cutout 678. The catch 682 comprises a forward-facing tapered edge 688 whichstarts at a forward edge of a ridge 689 formed on the end of the catch682 and which is orientated so that it extends in a direction away fromthe second section 604′. The catch 682 also comprises a smaller rearwardfacing tapered edge 690 which starts at a rearward edge of the ridge 689and which is orientated so that it extends in a direction towards fromthe second section 604′.

The diameter of the first aluminium tube 206 is greater than that of theinner wall 686 of the sheath 670. Therefore, the inner wall of the frontend of the sheath 670 has been cut away to provide a slot 692 into whichthe front end of the first aluminium tube 206 of the second pole 198 canbe slid. The tab 678 has a diameter relative to the axis 676 of thesheath 670 that is smaller than that of the aluminium tube 206 (theouter diameter of the tab 678 relative to the axis 676 of the sheath 670being the same as the inner diameter of the aluminium tube 206) so thatthe tab 670 locates inside of the aluminium tube 206 when the sheath 670is mounted on the end of the aluminium tube 206 (with the outer surfaceof the tab 678 located against the inner surface of the aluminium tube206 as shown in FIG. 32 ).

The front end of the first aluminium tube 206 of the second pole 198comprises one or more windows 694 which are located adjacent the frontedge of the first aluminium tube 206 of the second pole 198. The windows694 are of a suitable size so that, when the sheath 670 is mounted onthe front end of the aluminium tube 206, each window 694 can receive thecatch 682, the catch 682 being able to pass through each window 694 whenaligned with it. The windows 694 are located rearward from the frontedge of the aluminium tube 206 such that, when the catch 682 is locatedin a window 694, the front edge locates within the slot adjacent therear edge of the cut out 672. The second seal 210′ attached to the endof the first aluminium tube 206 in this embodiment includes an innercontour that forms a cut-out region extending from the front edge 673around each of the windows 694. As such, second seal 210′ in thisembodiment has a longer structure that extends deeper into the firstaluminium tube 206 than second seal 210 previously described.

The locking mechanism 200′ is attached to the first aluminium tube 206of the second pole 198 as follows.

The front end of the first aluminium tube 206 of the second pole 198 isslid into the front end of the sheath 670 by the front edge 673 of thefont end entering into and sliding rearwardly along the slot 692 of thefront end of the sheath 670. As the front end slides further into theslot, the front edge engages with the forward facing taper 688 of thecatch 682. Continued movement of the front edge 673 causes the tab 678to bend inwardly towards the axis 676 of the sheath 670 due to the shapeof the front taper 688 as it pushes the catch 682 out of the way. As thefront end of the aluminium tube 206 continues to enter the sheath 670,the end of the catch 682, which has been pushed inwardly out of the way,engages with and slides along the inside wall of the aluminium tube 206with the tab 678 locating inside of the aluminium tube 206. Thealuminium tube 206 continues to enter the sheath 670 until the catch 682aligns with a window 694 on the inside of the aluminium tube 206 (thismay require some rotation of the aluminium tube within the sheath 670).When the catch 682 aligns with the window 694, it moves outwardly toenter the window 694 due to the resilient nature of the tab 678 whichreverts back to its original shape. When the catch 682 is located insideof the window 694, it is held in place by the resilience of the tab 678which seeks to maintain its original shape. When the catch 682 islocated inside of the window 694, the base 684 of the tab 678 alignswith the inner wall of the sheath 670 so that they are flush with eachother with the outer surface of the tab 678 located against the innersurface of the aluminium tube 206 as shown in FIG. 32 .

After the sheath 670 is mounted on the end of the aluminium tube withthe catch 682 located within a window 694, the aluminium tube of thefirst pole 196 is inserted into the second section 604′ of the sleeve600′ and then into the end of the first aluminium pole 206 of the secondpole 198. When the aluminium tube of the first pole 196 has beeninserted into the end of the second pole 198, it is surrounded by thefirst aluminium tube 206 of the second pole 198, which in turn issurrounded by the sheath 670. The aluminium tube 206 of the first pole196 locates against the base 684 of the tab 678, preventing it frommoving perpendicularly to the plane of the cut out 672 as best seen inFIG. 32 . As such, the tab 678 is held sandwiched between the aluminiumtube of the first pole 196 and the first aluminium tube 206 of thesecond pole 198. As such, the catch 682 is prevented from leaving thewindow 694 in the first aluminium tube 206. Therefore, when the firstpole 196 is inserted into the second pole 198, the sheath 670 is lockedonto the second pole 198. The position of the first pole 196 can then belocked relative to the second pole 198 using the clamping mechanism inthe second section 604′.

In order to remove the sheath 670 from the first aluminium tube 206 ofthe second pole 198, the clamping mechanism of the second section 604′is released and the first pole 196 is first removed from the firstaluminium tube 206 of the second pole 198. The catch 682 is then pushedinwardly, moving it out of the window 694 into the first aluminium tube206. The sheath 670 can then be slid off the end of the first aluminiumtube 206 of the second pole 198, the catch 682 sliding along the insidewall of the first aluminium tube 206 of the second pole 198 as it doesso until it disengages with the second pole 198.

It will be appreciated that the second aluminium tube 208 of the secondpole 198 remains located inside of the first aluminium tube 206 of thesecond pole 198 during the procedure of attaching and using the lockingmechanism 200′ on the first and second poles 198.

Whilst the sheath 670 described above completely surrounds the end ofthe first aluminium tube 206 of the second pole 198, it will beappreciated that the sheath 670 can partly surround the tube 206, thesheath 670 extending in a circumferential direction around the firstaluminium tube 206 sufficiently to enable the sheath 670 to slide on anoff the end of the first aluminium tube 206 in an axial direction butprevent the sheath 670 from being removed from the first aluminium tube206 in another direction e.g. perpendicular to the axis 676 of the firstaluminium tube 206.

Whilst in the embodiment, the cross sectional shapes of the aluminiumtube the first pole 196 and the cross-sectional shape of first aluminiumtube 206 of the second pole 198 are oval, it will be appreciated thatthe shape of cross sections could be over shapes such as round, square,rectangular triangular etc. whilst the design of the first section 602′could still function in the same manner.

The pivot mechanism 110 will not be described with reference to FIGS. 4,15 and 16 .

Attached to the end of the first pole 196 in a fixed manner is an endhousing 220 (see FIGS. 1 and 2 ) comprising two clam shells 222 attachedto each other using screws (only one clam shell is shown in FIG. 4 ).The pivot mechanism 110 connects the sanding head 100 to the first pole196 via the end housing 220.

The pivot mechanism 110 comprises a fork 224 having two arms 226, acentral interconnecting section 228 and a pole support section 230. Thetwo arms 226 extend in parallel in a forward direction from the ends ofthe central interconnecting section 228 in a symmetrical manner. Thepole support section 230 connects to the centre of the interconnectionsection 228 on the opposite side of the two arms 226 and projects in arearward direction opposite but parallel to that of the two arms 226.

Formed in each side of the gear housing 122 in a symmetrical manner arethreaded apertures. The axis 232 of the of the apertures are alignedwith each other and are horizontal. Formed in the ends of the two arms226 are apertures. When the fork 224 is attached to the sanding head100, the ends of the two arms 226 align with the apertures formed in thegear housing. A bolt 233 is passed through each aperture in the end ofeach arm 226 and screw into the threaded aperture in the side of thegear housing 122 to attach the fork 224 in a pivotal manner. The fork224 can pivot around the bolts 233 about a horizontal sideways axis 232.

Rigidly mounted in a recess formed in the end of the pole supportsection 228 is the rear half of an axle 234. The axle 234 projectsrearwardly. Formed in the end housing 220 is an elongate recess 236. Therecess 236 extends in a direction parallel to the longitudinal axis ofthe first pole 196. The forward half of the axle 234 is mounted insideof the recess 236 via two bearings 240 supported by the end housing inthe side walls of the recess. The bearings 240 allow the axle to rotatewithin the recess. The axle can rotate about an axis which is parallelto the longitudinal axis of the first pole 196 and which passes throughthe length of the second smaller passage 148 of the elongate body 102.This allows the fork 224, together with sanding head 100, to pivot aboutan axis which is parallel to the longitudinal axis of the first pole 196and which passes through the length of the second smaller passage 148 ofthe elongate body 102. The axis also crosses the output axis 126 of thedrive spindle.

The sanding head 100 has a centre of gravity 242. As best seen in FIG.15 , the axis of pivot 232 of the fork 224 on the sanding head 100 islocated forward (distance D in FIG. 15 ) of the centre of gravity 242.Furthermore, the axis of pivot 232 of the fork 224 on the sanding head100 is located forward of the drive axis 126 of the output spindle 118.This allows the sanding head 100, which can freely rotate about thebolts 233, to automatically pivot to an angular position where it isparallel to a wall when the sanding head 100 is raised by an operator.

When the plane of the platen 116 is parallel to the longitudinal axis ofthe elongate body 102 as shown in FIG. 16 , the axis of rotation of theaxle is located below the centre of gravity 242 of the of the sandinghead 100.

The design of the platen 116 will now be described with reference toFIGS. 17 and 18 .

The platen 116 comprises a plastic disc 244 with a metal insert 246located at the centre. Attached to the bottom of disk is layer made of asoft foam 248. Attached on the opposite side of the soft foam layer is asheet of Velcro (not shown). The Velcro is used to attach the sandpaperto the platen 116.

The platen 116 is attached to the output spindle 118 using a bolt 252.The platen 116 is circular and extends radially from the drive axis 126in a direction perpendicular to the drive axis 126. Two sets of airholes 254, 256 are formed through the platen 116 to allow air and debristo pass through the platen 116. The first set 254 are located towardsthe outer edge of the platen and in a symmetrical manner around the axis126. The holes 254 of the first set are tear shaped with the narrowerend pointing towards the centre. The straight sides of the holes 254align with the centre of the platen 116. The second set of holes 256 arelocated between the first set 254 and the centre of the platen 116 in asymmetrical manner. The holes 256 of the second set are smaller thanthose of the first set. The holes 256 of the second set are tear shapedwith the narrower end pointing towards the centre. The straight sides ofthe holes 256 align with the centre of the plate 116.

Referring to FIG. 6A, a space 258 is formed between the top of theplaten 116 and the underside of the hood 112. In the present design, thesize H of the space is kept to a minimum. This ensures that the airspeed above the platen 116 is kept as high as possible. If the air speedslows, entrained dust and debris will deposit on the surface of theunderside of the hood 112 and therefore will build up. By keeping theair speed high, the dust remains entrained and therefore can be drawnout the flexible pipe 128 due to the suction from a vacuum cleaner.

The air flow around the rotating platen 116 is improved due to the innercircular inner wall 162 which is adjacent the outer edge of the platen116. The inner wall 162 locates between the edge of the paten and thebristles 182 of the brush ring 132. The inner wall 162 guides the movingair in a smooth manner and minimises the amount of contact between themoving air and the bristles 182 of the brush ring 132. If the moving airwere to come into contact with the bristles 182, the air flow wouldbecome non-uniform as its passes through the bristles 182. Furthermore,the use of the inner wall 162 to separate the bristles 182 from the edgeof the platen 116 minimises the amount of dust and debris that collectswithin the bristles 182.

The cross-sectional area of the gap 260 between the inner wall 162 andthe edge of the platen 116 (shown by the hatchings 262 in FIG. 6B) isthe same as that of the cross-sectional area of the flexible pipe 128which in turn is the same as that of the first passageway 154 way in thetwo poles 196, 198.

Referring to FIG. 19 , the second pole 198 extends into the mountsection 136 of the rear housing 104. A part 270 of the side wall firstaluminium tube 206 of the second pole 198 has been removed to expose thesurface of the second aluminium tube 208. The control electronics 144are mounted in a control module. Where the part 270 of the firstaluminium tube has been removed, the control module 144 is mountedinside of the first aluminium tube 206 adjacent the second aluminiumtube 208. This enables heat generated by the electronic module 144 to betransferred to the second aluminium tube 208 which is a good heatconductor and transfer the heat away from the control module 144.Furthermore, during the operation of the pole sander, air is drawnthrough the second aluminium tube 208 by a vacuum cleaner. The air flowacts to cool the second aluminium tube 208 which in turn acts to coolthe electronic module 144.

The control electronics 144 are connected directly to the motor 114using a single electrical cable 146 which carries the wires use toprovide the electrical current to the windings of the brushless motor114. One end of the cable 146 connects directly to the controlelectronics 144 via a soldering tag 272 which connects to electricinterface 274. The other end connects directly to the motor 114. Thecable 146 is continuous with no plugs or connectors being used so asavoid interfering with the signals generated by the control electronics144 which are sent down the cable 146 to operate the motor 114. Acentral section 276 of the cable 146 located inside of the two poles196, 198 is helical to enable the length of the cable 146 in a directionparallel to the longitudinal axis of the poles 196, 198 to extend orreduce depending on the relative telescopic positions of the two poles196, 198. When the cable 146 exit the first pole 196 and pass across thepivot mechanism 110, it locates against the side of flexible pipe 128 asshown in FIG. 21 . In order to maintain the position of the cable 146relative to the flexible pipe 128, a tubular sheath 278 surrounds boththe cable 146 and the flexible pipe 128 as shown in FIGS. 26 and 27 .

An extension tube 280 connects to the end of the second aluminium tube208 of the second pole 198 which extends the first passageway 154 of thesecond pole 198 through the rear handle section 138 of the rear housing104 and projects rearwardly of the handle section 138. The extensiontube 280 is made from electrically conductive material and iselectrically connected to the second aluminium tube 208. A vacuum nozzle152 is releasably attachable to the end of the extension tube 280 via aclip 282. The vacuum nozzle 152 is made from electrically conductivematerial and is electrically connected to the extension tube 280. Theclip 282 comprises a first part formed on the vacuum nozzle 152 and asecond part formed on the end of the extension tube 280. The first partcomprises two pins 284, each pin 284 being mounted on the end of aresiliently deformable leg 286. The second part comprise two holes 288formed through the side wall of the end of the extension tube 280 incorresponding locations to the pins 284. To attach the vacuum nozzle152, the legs 286 are bent inwardly so that the pins 284 can slideinside of the end of the extension tube 280 as the vacuum nozzle 152 isslid into the extension tube 280. When the pins 284 align with the holes288, the pins 284 are biased into the holes 288 by the resilient legs286 bending back to their original position. Whilst the pins 284 arelocated in the holes 288, the vacuum nozzle 152 remains attached to theextension tube 280. To detach the vacuum nozzle 152 the pins 284 arepushed back into the apertures to disengage them from the holes 288. Thenozzle 152 is slid out of the extension tube 280. The vacuum nozzle 152can be attached to the hose of a vacuum cleaner. As the nozzle 152 canbe easily attached and detached, a suitable design of nozzle 152 can bechosen depending on the type of vacuum cleaner utilised. Furthermore, ifthe nozzle 152 breaks it can be easily replaced.

The foregoing description of the embodiments has been provided forpurposes of illustration and description. It is not intended to beexhaustive or to limit the disclosure. Individual elements or featuresof a particular embodiment are generally not limited to that particularembodiment, but, where applicable, are interchangeable and can be usedin a selected embodiment, even if not specifically shown or described.The same may also be varied in many ways. Such variations are not to beregarded as a departure from the disclosure, and all such modificationsare intended to be included within the scope of the disclosure.

The invention claimed is:
 1. A locking mechanism for a power tool havinga first pole and a second pole, the locking mechanism being configuredto lock a position of the first pole to the second pole, wherein thefirst pole is telescopingly movable in and out of the second pole andthe second pole includes at least one recess, the locking mechanismcomprising: a first section configured to connect to the second pole anda second section configured to connect to and lock the position of thefirst pole, wherein the first section comprises: a sheath mountable onand surrounding at least part of the second pole; a cut out formed in awall of the sheath; a resilient tab connected to the sheath and fixedlyextending from an edge of the cut out to radially align with at least aportion of the cut out; and a catch formed on the tab and extendingradially outwardly from the tab; wherein the catch is configured tolocate within the recess of the second pole to securely mount the sheathon the second pole.
 2. The locking mechanism of claim 1, wherein therecess comprises a window extending through a wall of the second pole.3. The locking mechanism of claim 2, wherein the catch extends throughthe window.
 4. The locking mechanism of claim 1, wherein the catchcomprises a taper.
 5. The locking mechanism of claim 1, wherein thesheath is mounted on and surrounds an end of the second pole.
 6. Thelocking mechanism of claim 1, wherein the resilient tab is fixedlyconnected at an end of the tab to the sheath.
 7. The locking mechanismof claim 1, wherein the cut out is rectangular in shape, wherein alonger edge of the cut out extends in a direction parallel to alongitudinal axis of the sheath, and wherein the tab connects to ashorter edge of the cut out.
 8. The locking mechanism of claim 1,wherein the tab extends in a direction parallel to a longitudinal axisof the sheath.
 9. The locking mechanism of claim 1, wherein at least aportion of the tab is planar.
 10. The locking mechanism of claim 9,wherein the catch is formed on the tab adjacent an end of the tab andthe catch extends in a direction perpendicular to a plane of the tab,and wherein the tab is flexible to allow the catch to move in adirection perpendicular to a longitudinal axis of the sheath.
 11. Thelocking mechanism of claim 1, wherein the tab locates inside of thesecond pole and the catch projects from inside of the second pole intothe recess; and wherein, when the first pole is located inside of thesecond pole, the first pole locates behind the tab to prevent movementof the tab and lock the catch within the recess.
 12. A power toolcomprising: a telescopic pole including a first pole configured totelescopingly move in and out of a second pole, wherein the second polecomprises a recess; a locking mechanism comprising a first sectionconfigured to connect to the second pole and a second section configuredto connect to the first pole, wherein the first section comprises: asheath mountable on and surrounding at least part of the second pole; aresilient tab fixedly connected to the sheath; and a catch formed on thetab; wherein the catch is configured to locate within the recess of thesecond pole to securely mount the sheath on the second pole, wherein thetab locates inside of the second pole and the catch projects from insideof the second pole into the recess; and wherein, when the first pole islocated inside of the second pole, the first pole locates behind the tabto prevent movement of the tab and lock the catch within the recess. 13.The power tool of claim 12, wherein the recess comprises a windowextending through a wall of the second pole, wherein the catch extendsthrough the window.
 14. The power tool of claim 12, wherein the lockingmechanism comprises a cut out formed in a wall of the sheath, the tabbeing connected at an end of the tab to an edge of the cut out, the tabextending, at least in part, parallel to the plane of the cut out,wherein at least a part of the tab extends within the plane of the cutout.
 15. The power tool of claim 14, wherein the cut out is rectangularin shape, wherein a longer edge of the cut out extends in a directionparallel to a longitudinal axis of the sheath, and wherein the tabconnects to a shorter edge of the cut out.
 16. The power tool of claim12, wherein the tab extends in a direction parallel to a longitudinalaxis of the sheath.
 17. The power tool of claim 12, wherein at least aportion of the tab is planar, the catch is formed on the tab adjacent anend of the tab and the catch extends in a direction perpendicular to aplane of the tab, and the tab is flexible to allow the catch to move ina direction perpendicular to a longitudinal axis of the sheath.
 18. Amethod of attaching the locking mechanism of claim 12 to the second poleof the power tool, comprising the step of: 1) sliding the sheath of thelocking mechanism onto an end of the second pole; 2) continuing to slidethe sheath onto the end of the second pole until a front edge of thesecond pole engages with a taper of the catch; 3) continuing to slidethe sheath onto the second pole to cause the catch to move out of theway of the second pole by bending the resilient tab with the front edgeof the second pole slidingly engaging the taper; 4) continuing to slidethe sheath onto the second pole as the catch slides alongside aninterior of a wall of the second pole; and 5) continuing to slide thesheath onto the second pole until the catch aligns with the recess andengages the recess under a biasing force of the resilient tab.
 19. Alocking mechanism for a power tool having a first pole and a secondpole, the locking mechanism being configured to lock a position of thefirst pole to the second pole, wherein the first pole is telescopinglymovable in and out of the second pole and the second pole includes atleast one recess, the locking mechanism comprising: a first sectionconfigured to connect to the second pole and a second section configuredto connect to and lock the position of the first pole, wherein the firstsection comprises: a sheath mountable on and surrounding at least partof the second pole; a resilient tab fixedly connected to the sheath; anda catch formed on the resilient tab; wherein the catch is configured tolocate within the recess of the second pole to securely mount the sheathon the second pole, wherein the tab locates inside of the second poleand the catch projects from inside of the second pole into the recess;and wherein, when the first pole is located inside of the second pole,the first pole locates behind the tab to prevent movement of the tab andlock the catch within the recess.
 20. The locking mechanism of claim 19,wherein the recess comprises a window extending through a wall of thesecond pole, and wherein the catch extends through the window.
 21. Thelocking mechanism of claim 19, wherein the resilient tab is connected atan end of the tab to the sheath.